Newly released findings from Bradley Hospital published in the Journal of Sleep Research have found that acute illnesses, such as colds, flu, and gastroenteritis were more common among healthy adolescents who got less sleep at night. Additionally, the regularity of teens’ sleep schedules was found to impact their health. The study, titled “Sleep patterns are associated with common illness in adolescents,” was led by Kathryn Orzech, Ph.D. of the Bradley Hospital Sleep Research Laboratory.

Orzech and her team compared three outcomes between longer and shorter sleepers: number of illness bouts, illness duration, and school absences related to illness. The team found that bouts of illness declined with longer sleep for both male and female high school students. Longer sleep was also generally protective against school absences that students attributed to illness. There were gender differences as well, with males reporting fewer illness bouts than females, even with similar sleep durations.

Orzech’s team analyzed total sleep time in teens for six-day windows both before and after a reported illness and found a trend in the data toward shorter sleep before illness vs. wellness. Due to the difficulty of finding teens whose illnesses were spaced in such a way to be statistically analyzed, Orzech also conducted qualitative analysis, examining individual interview data for two short-sleeping males who reported very different illness profiles. This analysis suggested that more irregular sleep timing across weeknights and weekends (very little sleep during the week and “catching up” on sleep during the weekend), and a preference for scheduling work and social time later in the evening hours can both contribute to differences in illness outcomes, conclusions that are also supported in the broader adolescent sleep literature.

“Some news reaches the general public about the long-term consequences of sleep deprivation, such as the links between less sleep and weight gain,” said Orzech. “However, most of the studies of sleep and health have been done under laboratory conditions that cannot replicate the complexities of life in the real world. Our study looked at rigorously collected sleep and illness data among adolescents who were living their normal lives and going to school across a school term.”